1. Field of the Invention
The present invention generally relates to a system and method for high quality image reproduction. In particular, the invention relates to a system and method wherein received image-representing signals are processed to obtain resulting processed data, the resulting processed data is stored, the data thus stored is selectively read out in accordance with operator controlled inputs, and the data thus read out is utilized, in accordance with a gray line printing technique, to produce a high quality reproduction of the original image. An important advantage of the inventive system and method resides in the grayscale image "print while store" function.
2. Description of the Prior Art
There has been an increasing need within various medical, scientific and technical disciplines, for a technique and system for high quality image reproduction. The need for such an imaging technique has, in recent years, been satisfied by the system and method for high quality image reproduction disclosed in the aforementioned copending application Ser. No. 182,886 filed on Aug. 29, 1980, now U.S. Pat. No. 4,345,276 issued on Aug. 17, 1982.
Before the development of the method and system of the copending application, prior art systems were characterized by several substantial drawbacks: (1) prior art systems were quite slow, since various different processes (both automatic and manual) had to be interfaced; (2) prior art systems were inaccurate, this being the result of such factors as optical distortion and lack of accurate and automatic control of brightness, exposure, focus, etc.; (3) prior art systems produced reproductions of limited quality, the quality of reproduction being limited by the type of film employed, as well as the overall characteristics of the system; (4) prior art systems employed analog positioning systems which introduced error, involved interface of electrical, mechanical and manual operations, and were quite often very crude in their operation; and (5) finally, prior art systems were costly due to size and complexity, as well as maintenance and overhead associated with operation of the system, especially when the system was operated on a large scale.
The system and method of the present invention eliminated, to a very great extent, the analog processing, mechanical and optical operations which characterized systems of the prior art, and which caused such systems of the prior art to be hampered by disadvantages in the form of lack of speed, accuracy, quality and economy in system development and operation. More specifically, the system of the copending application took advantage of sophisticated digital processing technology, and implemented such technology so as to develop an integrated, self-contained system for high quality image reproduction. The result was a system which was not only automated but flexible. For example, users of the system of the copending application are able to introduce several different images (in the form of image-representing signals) into the system, and then to reproduce those images in any given order or arrangement on a simple printed sheet. As a further example, a user of the system can introduce a single image into the system, and can then easily obtain any number of direct duplicates arranged in any desired array on a printed sheet. Thus, the system and method of the copending application were and are sufficiently flexible to accommodate various modes of image reproduction, including those involving multi-formatting, while providing a true, high quality, analog-type image on paper.
Moreover, the system and method of the copending application provides a type of multi-formatting which is sufficiently flexible to allow various modes of image reproduction, including automatic image rotation (for example, through 90 degrees) prior to image reproduction. Of course, other modes of image reproduction may be employed to meet special requirements, such as those related to cardiac diagnosis (for example).
However, the system and method of the copending application were originally designed to incorporate a certain type of printer, specifically a Bell & Howell Model 912 printer. Subsequently, it has been deemed more desirable to utilize a Muirhead Electrostatic Printer, Model M-136 to replace the original printer in order to provide a superior quality image at a lower product cost. However, as is well known in the art, printers such as the Muirhead Printer operate at a much slower speed.
Therefore, it was recognized that it was highly desirable to redesign and improve on the system and method of the copending application in order to accommodate slower speed printers. In the process, it was further recognized that it was highly desirable to provide the system and method for high quality image reproduction with a "print while store" capability. Thus, whereas the previous system and method utilizing the Bell & Howell-type printer sequentially stored and printed grayscale images, the present system and method simultaneously store and print grayscale images using a lower cost, slower speed printer (such as the Muirhead Printer).